Expansion unit for mine ceiling support



May 3, 1966 F. A. TEEPLE, JR 3,243,997

EXPANSION UNIT FOR MINE CEILING' SUPPORT Filed Nov. 13. 1961 2 Sheets-Sheet 1 INVENTOR FRANK A.TEEPLE,J2. 33

ATTORNEYS y 1966 F. A. TEEPLE, JR 3,248,997

EXPANSION UNIT FOR MINE CEILING SUPPORT Filed Nov. 13, 1961 2 Sheets-Sheet 2 ATTORNEYS United States Patent 3,248,997 EXPANSION UNIT FOR MINE CEILING SUPPORT Frank A. Teeple, Jr., Huntington, W. Va., assignor to H. K. Porter Company, Inc., Pittsburgh, Pa., a corporation of Delaware Filed Nov. 13, 196i, Ser. No. 151,974

' 6 Claims. (CI. 8576) The invention relates generally to the art of mining and primarily seeks to provide a novel expansion unit for anchoring the roof suspension bolts by which mine ceiling or roof portions are supported.

Roof suspension bolts, or as popularly called, roof bolts, are now widely used. In the use of these bolts, holes are drilled vertically or sometimes at an angle, upwardly into the mine roof or ceiling, and supporting bolts directed through supporting plates or bars engaged with the roof or ceiling are inserted in the holes and anchored therein for securely supporting the engaged roof portions and portions adjacent thereto. The anchoring of the bolts is etfected by employment of expansion units inserted in the roof bores and through which the bolts are threaded, means being included which are effective upon threading home of the bolts to expand the units and cause them to firmly grip the wall portions defining the bolt receiving bores. It is a purpose of the present invention to provide a novel form of expansion unit which can be easily and economically manufactured, and which is subject to being inserted into a receiving bore with great facility and capable of very securely anchoring a rod threaded therethrough.

An object of the invention is to provide an expander unit of the character stated including integrally connected and laterally spreadable sections or wings shaped to present a generally cylindrical exterior for engagement in a mine ceiling bore, an expander plug having an internal bore therein and movable longitudinally between said wings, a nut element overlying said expander plug, the wings and the plug having cooperating cam surfaces effective when the plug is forced longitudinally downward by said overlying nut to force the wings apart, and a bolt threadable through the nut bore for moving the nut and its underlying plug longitudinally.

Another object of the invention is to provide an expander unit of the character stated in which the opposed and integrally connected wings are shaped to provide a generally cylindrical shell that encloses the plug and nut element as a self-retaining, three part assembly which does not come apart when subjected to rough handling as in mining usage.

Another object of the invention is to provide an expander unit of the character stated wherein the cooperative wedge camming edge portions are surfaces on the expander plug and the opposed and integrally connected wings are opposed in a relation for interlocking, as by undercutting, thereby assuring proper camrning pressure application during expanding of the unit, without danger of the wing edges being sprung outwardly beyond their camming surfaces on the expander plug.

A further object of the invention is to provide an expander unit of the character stated wherein the expander plug is provided with leg extensions therefrom and having wedge-shaped portions extending therefrom, the wedge-shaped extensions being formed as by fabricating.

Another object of the invention is to provide an expander unit of the character stated wherein the wedgeshaped extensions of the expander plug are provided with end slits or forks, thereby providing for initial point contact of the forks of said wedge-shaped extensions with the opposed carnming surfaces of the shell wing edges.

A further object of the invention is to provide an ex- 3,2483%? Patented May 3, 1966 pander unit of the character stated wherein the overlying nut element is provided with extended portions thereon so that the forces exerted upon said not will be tangential or across the extended portions of the same, thereby avoiding compressive force upon the thread members thereof and a possible resultant jamming of the nut and its cooperating bolt.

A further object of the invention is to provide an expander unit of the character stated wherein the upper surface of the expansion plug is provided with holding means so as to prevent free turning of its overlying nut.

A still further object of the invention is to provide an expander unit of the character stated wherein the arcuate shaped wing portions are provided with weakening longitudinal grooves therein, so that upon operational engagement of the expander plug within the opposed edges of said shell member, a further outward bulging along the arcuate surface of the shell will occur, thus effecting an engagement of the shell with a larger area of the mine ceiling bore.

A still further object of the invention is to provide an expander unit of the character stated wherein the expansion plug is fabricated from separable elements which are then joined together.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a longitudinal view showing a mine ceiling bore in section and an expander unit placed in position therein for being anchored in the bore by turning of the anchor bolt.

FIGURES 2 and 3 are horizontal sectional views taken respectively on the lines 22 and 3-3 of FIGURE 1.

FIGURE 4 is an in part side elevational and in part vertical cross sectional view of the wedge plug and its separate overlying nut element.

FEGURE 5 is a bottom plan view of the Wedge plug taken along line 55 of FIGURE 4.

FIGURE 6 is a top plan view of the wedge plug taken along line 66 of FIGURE 4.

FIGURE 7 is a bottom plan view of the separate overlying nut element of the wedge plug taken along line 'l''? of FIGURE 4.

FIGURE 8 is a side sectional view of the wedge plug and its separate overlying nut element taken along line 88 of FIGURE 4.

FIGURE 9 is a top plan view of a modified form of wedge plug.

7 FIGURE 10 is a front elevational view of the modified wedge plug of FIGURE 9.

FIGURE 11 is a side elevational view partly in section of the modified wedge plug taken along line 1111 of FIGURE 9.

FIGURE 12 is a fragmentary perspective view of an expansion unit shell wing having longitudinal scores therein.

FIGURE 13 is a sectional View similar to FIGURE 3 in which the effect of providing the longitudinal scores is depicted.

In the example of embodiment of the invention herein disclosed, a section of the mine roof ceiling is shown at 5, the same being provided with a drill hole 6 in which to receive the expansion unit generally designated 7. The unit serves as an anchoring means for the threaded bolt 3 with its head 9 bearing against the plate 10 which, in turn, supports the roof or ceiling as indicated at 11 in FIGURE 1.

The improved expansion unit, generally designated 7, includes an integral shell generally designated 12, best illustrated in FIGURE 1 and in the partial perspective view of FIGURE 12, and preferably formed from a flat metal blank, and a wedge plug generally designated 13. When the parts are completely shaped and properly assembled, the wedge plug is held within the shell against inadvertent fall-out in a manner to be described hereinafter, and as shown in FIGURE 1.

The shell 12 is formed into the generally cylindrical shape partially depicted by FIGURE 12 and then about the wedge plug as shown in FIGURE 1. The shell includes arcuate Wing portions 14 and a central ring-like portion .15 traversed centrally by an abutment bar 16, the wing portions 14 being integrally connected to the ringlike portion 15 by relatively narrow connecting members or straps 18. The side edges 19 of the wing portions are designed as camming surfaces and diverge symmetrically with relation to the longitudinal center line of said shell and from the wing portion ends proximal to the ring-like portions 15 toward the wing portion ends remote from said ring-like portion. If desired, the wing portions 14 may be shaped to provide cross-axial grooved indents therein and resultant high points therebetween. Such grooves formed on the bore wall side of the expanding shell member are in widespread use and although they induce contact with the bore hole and the shell, thus effecting a better grip, such grooves are not shown and are in no way an object of the present invention.

The wedge plug may be cast or forged as indicated in FIGURES 4 to 8 or may be fabricated or assembled from separate elements as shown in FIGURES 9 to 11. The cast or forged wedge plug 13 includes a generally cylindrical body 22 having a bore 23- formed axially therethrough and adapted to accommodate the anchoring bolt 8. The plug 13 further includes two side leg dependencies 24 and these and the body 22 are shaped to provide wedge shaped extensions 25 having camming edges 26 which may be undercut. The dependencies or legs 24 also include radially outwardly presented shoulder portions 27 which merge with the cylindrical exterior of the plug body 22.

The fabricated or assembled Wedge plug also includes a generaly cylindrical body 41 having a bore 42 formed axially therethrough and of such size as to accommodate the anchoring bolt 8. The plug 40 also further includes side leg dependencies 43. A separately fabricated wedge shaped member 44 having camming edges 46 is secured to the plug body 41 and along its side leg dependency 43 on each side thereof, that is, a pair of wedge members is attached to the plug body 41, one along each side leg dependency 43. The thus formed wedge shaped projections 44 are, as shown in FIGURES 10 and 11, provided with spaced holes 28 which may be placed therein as by boring, cutting, punching or other generally known practices. Holes 28 are provided in the Wedge members 44 as contact or securement points through which the wedge members 44 may be brazed or welded to the plug body 41 and its side leg dependencies 43. The above form is a preferred embodiment of the invention and as such is representative of how the Wedge shaped members 44 can be attached to the basic plug body.

In many cases .the formation of the wedge plug 40 from two or more initial components which are then secured together, presents advantages over the one piece construction. With the representative arrangement as shown by FIGURES 9-11, the basic body member 41, 43' can be composed of less expensive material and further, more cheaply fabricated, it being clear that the operational forces present in the use of the expander plug unit are primarily upon the wedge shaped projection 44. Furthermore by the provision of a separate not which tangentially absorbs the forces applied thereto, the need of a threaded wedge plug is obviated.

It is often desirous to provide the ends of the wedgeshaped extensions 25, 44 with a forked or bifurcated end designated 29, 45 respectively, and as best shown in FIG- URES 4, 8 and 10. Through such provision initial contact at points 36 between the Wedge plug and the cooperating camming surfaces 19 of shell 12 is provided upon the assembly of the two units. It is to be understood that separate prongs of such a split or forked end are forced together upon the downward movement of the Wedge plug between the opposed camming Wing edge surfaces thus presenting smooth camming surfaces thereon.

The wedge plug is further provided with a separate cooperating overlying nut element generally designated 30. The nut element is of general cylindrical shape having a threaded bore 31 centrally disposed therein for receiving the anchoring bolt 8. The nut may be crowned from side to side as at 32 and preferably includes tangentally extending side areas coming to a point and best indicated at 33. The extended portions of the nut cooperate with the arcuate wedge-shaped upstanding portions 34, 47 of wedge plugs 13, 40 respectively from their side leg dependencies 26 and are therefore, preferably in opposed relationship to each other. Such arcuate wedgeshaped members 34 may be formed integrally to body member 22, or in the case of the modification as shown in FIGURE 10, formed as part of the wedge-shaped element 44 and in either case may be provided with an inner and downwardly extending chamfer 35.

The operational and pre-operational descriptions of the expansion unit are in particular directed to the plug unit as shown by FIGURES 48, it being obvious that the separately fabricated embodiment of FIGURES 9-11 functions in the same manner.

In conditioning the expansion unit for use, the shell 12 is bent about its central ring-like portion 15 and the center abutment 16 thereof so as to conform to the wedge plug 13 as shown in FIGURE 1. The camming surfaces 19 of the expander shell will then be presented in camming relationship to the undercut wedge camming edges 26 of the wedge plug. It will also be apparent by reference to FIGURE 1 that when the shell 12 has thus been disposed about the wedge plug, the plug is slidable longitudinally within the shell. By reason of the envelopment of the plug leg dependencies 24 and the body 22 by the camming edges 19 of the shell 12 and the interfitting of the camming edges 26 of the plug between the above mentioned shell camming edges, the shell and wedge plug becomes so interfitted as not to be able to be shaken loose from each other. The forked ends 29 of wedge portions 25 will, as is illustrated in FIGURE 1, present themselves for initial contact at points 36 with camming surfaces 19 of the expandable shell thereby further assuring co-assembly of the shell and wedge plug without danger of being shaken apart.

Prior to the assembly of the shell about the wedge plug, nut member 30 is disposed so as to present its extended and pointed sides 33 in engagement with the upstanding arcuate wedge-shaped portions 34 of the wedge plug itself. Thus, it is apparent that upon the shaping of shell 12 about the wedge plug 13 the nut 30 is presented in overlying engagement with the plug member and disposed between the plug member 13 and the shell 12. Thus the nut also becomes a part of the entire assemblage and is held in position so as not to be shaken free from the unit upon rough handling such as is expected during mining use.

In operation of the expander unit, the cooperating bolt 8 is threaded into the receiving bore 31 of the cooperating nut 30 after passing through the bore 23 of the expander unit plug and after insertion through the receiving bore in the anchor plate 10. The unit then is inserted into the mine ceiling bore 6 in the manner as illustrated in FIGURE 1. Upon turning of the bolt and after its contact with the abutment bar 16, the nut being held against free movement by its cooperation with the upstanding wedge extensions 34 of plug member 13 will (.3 be forced in a downward direction thus contacting the body portion 22 of the plug. It can be seen that further turning will cause, through the action of the nut upon the plug, the plug to be forced further between the shell wings. During the initial movement of the plug between the presented camming edges 19 of the shell 12 the bifurcated ends 29 of the wedge-shaped projection 25 will be inwardly forced together and thus present the edges 26 in more complete contact with edges 19. It is apparent that initial contact being between the shell camming surfaces 19 and the bifurcated ends 29 of wedge member 26 at points 36, that the initial expansion pressure upon the shell wings will be located down near the free ends of the wings instead of being exerted simultaneously along the entire length of the shell wing edges 19. Thus it is further apparent, during the initial expansion, that the lower free end portions of the wings are first expanded into engagement with the bore defining walls, thus assuring securement thereto prior to the more complete shell wing expansion taking place upon full pressure contact between camming surfaces 26 and 19.

Because of the cooperative engagement of the wedging or camming surfaces 26, 19 as shown in FIGURES l, 3 and 13, the body portion of the shell will be laterally spread apart from the strap connections 18 and will thus be forced further and further into the ceiling bore walls so as to firmly and securely anchor the expansion unit and the supported ceiling anchor plate in place.

It will also be apparent by the perusal of the instant structure that as the overlying nut is downwardly forced, thereby in turn forcing the wedge plug between the shell wings, there can also be an outward deflection of the lower extremities of the plug 13 so that the engagement thereof in the ceiling bore may further contribute toward the anchoring of the unit. This spreading of the plug dependencies as well as reshaping of the wings gives more complete circular contact pressure in the bore hole thereby contributing to more even anchoring.

Upon shaping of the shell member about the wedge plug and its overlying nut the clearance between the abutment bar and the overlying nut must be less than the longitudinal distance to which the overlying nut is received into contacting position with the upper portion of the wedge plug, that is, in position between the arcuate wedge-shaped extensions 34. This not only assures the desired operability but, because the forces exerted upon the overlying nut in its coaction with the wedge plug extensions 34 are, as can be seen from FIGURE 2, tangential to the nut body itself and across its pointed extension, radial compressive straining of the overlying plug and resultant deformation of the nut and its threads such as might cause a locking of the nut threads with the engaging bolt is avoided. This assures that there can be a recovery of all bolts which it may be desired to remove from a mine ceiling after the room has been worked. This is important from the standpoint of avoiding wastage of metal (both bolts 8 and plates 10), thus atfording a substantial cost saving.

Also, it will be apparent from FIGURE 3 that the outward facing abutment shoulders 27 on the plug legs will assure against radial inward deflection of the wing edges. It will also be observed by reference to the drawings, and in particular FIGURES 3 and 13, that the undercut camming surfaces 26 of the wedge plug itself are angled downwardly and outwardly with relationship to the plug axis, thus being effective in spreading the shell wing edges 19 outwardly and apart as well as the main central portions of the wings, thus further contributing toward more complete shell contact with the mine ceiling walls.

Another feature of the present invention is apparent from FIGURE 12 wherein the arcuate-shaped wings are provided with longitudinal weakening scores or grooves 20, which when placed into use will provide for a more pronounced bulging of the central portion of the shell as more readily seen by reference to FIGURE 13. Providing weakening scores not only assures provision of an increased area for contact with the mine ceiling bore, such as would be particularly useful in working an oversized bore, but also assures a more complete contact between the carnming surfaces 26 of the wedge plug and the lateral wing sides 19 of the shell itself.

While preferred form and part arrangements have been shown in illustrating the invention, it is to be clearly understood that various changes in details and part arrangements may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim: 7

1. In a unit of the character described, a body shell and expander plug unit comprising a body shell including laterally spreadable opposed wings free of one another at lower end extremities and connected at upper extremities, said wings being shaped to provide arcuate exteriors for engagement in a mine ceiling bore and present opposed edge portions providing longitudinally converging camming surfaces, an expander plug confined between said wings and slidable longitudinally therebetween having a nut receiving portion disposed on the top thereof, and a wedge-shaped outward projection extending from each side thereof for wing spreading camming engagement and confinement against fall-out between said opposed camming edges of said wings; and a nut element separate from said expander plug and having an internally threaded bolt receiving bore therethrough and overlying said expander plug, said nut receiving portion of the expander plug being engageable with sides of the nut element to fix said nut element against free rotational movement.

2. A unit as defined in claim 1 wherein the overlying nut element is formed with an exterior projection for receiving compressive forces thereon in a tangential direction.

3. A unit as defined in claim 1 wherein the wedge camming edges on the Wings and the wing spreading camming surfaces on the Wedge shaped outward projections on the expander plug are shaped to cooperatively interlock as the plug is moved along the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections, said wings each being provided with at least a pair of weakened areas extending longitudinally thereof along the internal surface of each of said wings adjacent to the edges.

4. A unit as defined in claim 1 wherein the lower end portions of said wedge-shaped projections are provided with forked ends placed to provide initial contact points between said opposed wing edge camming surfaces and said expander plug.

5. A unit as defined in claim 1, wherein each of the wedge-shaped outward projections has holes therethrough, said holes containing securing means in contact with the expander plug and the wedge-shaped outward projections.

6. In a unit of the character described, a body shell and expander plug unit comprising a. body shell including laterally spreadable opposed wings free of one another at lower end extremities and connected at upper extremities, said wings being shaped to provide arcuate exteriors for engagement in a mine ceiling bore and present opposed edge portions providing longitudinally converging camming surfaces, an expander plug confined between said wings and slidable longitudinally therebetween having a nut receiving portion disposed on the top thereof, and a wedge-shaped outward projection extending from each side thereof for wing-spreading cam-ming engagement and confinement against fall-out between said opposed carnming edges of said wings, a nut element having an internally threaded bolt receiving bore therethrough and overlying said expander plug, said nut being engageable with said nut receiving portion of th expander plug to be held thereby against free rotational movernzent, said shell wings each being provided with at least a pair of weakened areas extending longitudinally thereof along the internal surface of said wings adjacent to the edges so as to permit a further outward bulging of said generally cylindrical wings upon operational contact of said wings by said expander plug.

References Cited by the Examiner UNITED STATES PATENTS 8 9/1916 Clements 85- -75 10/1925 Tomkinson 85-85 12/ 1925 Tomkinson 85 85 3/1932 Rasmussen 8576 7/1956 Dempsey 85-76 2/ 1962 Dempsey 8576 12/1963 Teeple 8576 4/ 1965 Teeple.

FOREIGN PATENTS 3/1934 France.

EDWARD c. ALLEN, Primary Examiner.

C. B. ELDERKIN, Assistant Examiner. 

1. IN A UNIT OF THE CHARACTER DESCRIBED, A BODY SHELL AND EXPANDER PLUG UNIT COMPRISING A BODY SHELL INCLUDING LATERALLY SPREADABLE OPPOSED WINGS FREE OF ONE ANOTHER AT LOWER END EXTREMITIES AND CONNECTED AT UPPER EXTREMITIES, SAID WINGS BEING SHAPED TO PROVIDE ARCUATE EXTERIORS FOR ENGAGEMENT IN A MINE CEILING BORE AND PRESENT OPPOSED EDGE PORTIONS PROVIDING LONGITUDINALLY CONVERGING CAMMING SURFACES, AN EXPANDER PLUG CONFINED BETWEEN SAID WINGS AND SLIDABLE LONGITUDINALLY THEREBETWEEN HAVING A NUT RECEIVING PORTION DISPOSED ON THE TOP THEREOF, AND A WEDGE-SHAPED OUTWARD PROJECTION EXTENDING FROM EACH SIDE THEREOF FOR WING SPREADING CAMMING ENGAGEMENT AND CONFINEMENT AGAINST FALL-OUT BETWEEN SAID OPPOSED CAMMING EDGES OF SAID WINGS; AND A NUT ELEMENT SEPARATE FROM SAID EXPANDER PLUG AND HAVING AN INTERNALLY THREADED BOLT RECEIVING BORE THERETHROUGH AND OVERLYING SAID EXPANDER PLUG, SAID NUT RECEIVING PORTION OF THE EXPANDER PLUG BEING ENGAGEABLE WITH SIDES OF THE NUT ELEMENT TO FIX SAID NUT ELEMENT AGAINST FREE ROTATIONAL MOVEMENT. 